xAI TTS → OpenAI-compatible proxy for OpenClaw (workaround for openclaw/openclaw#48454)

xai-tts-proxy.js

// xAI TTS → OpenAI-compatible proxy
// Translates OpenAI /v1/audio/speech requests to xAI /v1/tts
// Usage: XAI_API_KEY=xai-... node xai-tts-proxy.js
//
// OpenClaw config:
//   messages.tts.provider = "openai"
//   messages.tts.openai.baseUrl = "http://127.0.0.1:18790/v1"
//   messages.tts.openai.apiKey = "sk-proxy-not-needed"
//
// Voice mapping (OpenAI → xAI):
//   alloy→eve, echo→rex, fable→ara, onyx→leo, nova→sal
//   xAI native names (eve, ara, rex, sal, leo) also work directly.

const http = require("http");
const https = require("https");

const PORT = process.env.PORT || 18790;
const XAI_API_KEY = process.env.XAI_API_KEY;

if (!XAI_API_KEY) {
  console.error("XAI_API_KEY is required");
  process.exit(1);
}

const VOICE_MAP = {
  alloy: "eve", echo: "rex", fable: "ara", onyx: "leo", nova: "sal", shimmer: "eve",
  eve: "eve", ara: "ara", rex: "rex", sal: "sal", leo: "leo",
};

const server = http.createServer((req, res) => {
  if (req.method !== "POST" || !req.url.endsWith("/audio/speech")) {
    res.writeHead(404);
    res.end("Not found");
    return;
  }

  let body = "";
  req.on("data", (chunk) => (body += chunk));
  req.on("end", () => {
    let parsed;
    try { parsed = JSON.parse(body); } catch {
      res.writeHead(400);
      res.end("Invalid JSON");
      return;
    }

    const voice = VOICE_MAP[parsed.voice] || "eve";
    const format = parsed.response_format || "mp3";

    const xaiBody = JSON.stringify({
      text: parsed.input,
      voice_id: voice,
      language: "auto",
      output_format: {
        codec: format === "opus" ? "mp3" : format,
        sample_rate: 24000,
        bit_rate: 128000,
      },
    });

    const xaiReq = https.request("https://api.x.ai/v1/tts", {
      method: "POST",
      headers: {
        Authorization: `Bearer ${XAI_API_KEY}`,
        "Content-Type": "application/json",
        "Content-Length": Buffer.byteLength(xaiBody),
      },
    }, (xaiRes) => {
      res.writeHead(xaiRes.statusCode, {
        "Content-Type": xaiRes.headers["content-type"] || "audio/mpeg",
      });
      xaiRes.pipe(res);
    });

    xaiReq.on("error", (err) => {
      console.error("xAI request failed:", err.message);
      res.writeHead(502);
      res.end("xAI TTS request failed");
    });

    xaiReq.write(xaiBody);
    xaiReq.end();
  });
});

server.listen(PORT, "127.0.0.1", () => {
  console.log(`xai-tts-proxy listening on 127.0.0.1:${PORT}`);
});